The invention relates to a motor vehicle with a tailgate or the like.
Vehicles, in particular passenger cars, usually have, in the region of the vehicle tail, a tailgate which is closed or can be opened. In order to ensure sufficient accessibility to the compartment covered by the tailgate (in particular the trunk), and in order to avoid the risk of injury to individuals when the tailgate is open, said tailgates are configured such that they project beyond the outer contours of the vehicle, in particular such that they project beyond the top edge of the vehicle or else project laterally on the vehicle in the open state. Furthermore, these tailgates are often provided with pneumatic springs or the like which, once the tailgate has been unlocked, cause the latter to spring automatically into its open position. It may be the case here that, when the tailgate springs into the open position, it comes up against obstacles, for example, in a garage, the ceiling of the latter, with the result that the exterior of the tailgate is damaged. Furthermore, it may be the case that, with tailgates which are provided with an opening aid, the opening aid being actuated by remote control and the tailgate having been unlocked, the tailgate could swing into an individual standing in front of it as it springs open. This is also undesirable since injuries may be caused.
The object of the invention is thus to provide a motor vehicle with a tailgate or the like in the case of which the situation where the tailgate comes up against an obstacle during the opening operation is actively avoided.
The invention integrates in the tailgate means which are designed for sensing objects at least during the opening operation, these means sensing the region over which the tailgate moves from its closed position into the open position (and, if appropriate, also vice versa). If an obstacle appears during this opening operation (or also during the closing operation), it is possible either for a warning signal to be transmitted (acoustically and/or optically) or else for the rest of the pivoting operation of the tailgate to be interrupted by suitable means. This actively avoids the situation where the tailgate strikes against objects (obstacles) during the opening operation (and likewise during the closing operation, if this is carried out manually or by means of a drive), with the result that it is not possible for anybody to be injured or for the tailgate to be damaged, in particular in the exterior region.
The term xe2x80x9ctailgatexe2x80x9d has been used up until now, and will continue to be used below, to define the trunk lid of hatchback or fastback sedans and also the tailgate of station wagons or vans as well as the rear loading doors of transporters and trucks.
In a development of the invention, the means for sensing objects are also designed for sensing objects located in the tail region of the motor vehicle, in particular other motor vehicles which are parking. This has the advantage that the means for sensing objects have a double function. On the one hand, they are used as a so-called opening brake, with the result that they sense an obstacle in the pivoting region of the tailgate during the opening operation and transmit the already mentioned warning signal or brake or stop the continuing opening operation. If the tailgate is closed, these means for sensing objects may be used as a so-called parking aid. Using optical and/or acoustic signals, this parking aid signals to the vehicle driver, as he/she is reversing, how much space still remains between his/her own vehicle and the vehicle behind, in order for it to be possible to make optimum use of the available space when parking. Consequently, the means can be used for two different purposes, as a result of which it is advantageously possible to cut back on the number of means required and the assembly outlay is reduced. Since such means for sensing objects, which in one configuration of the invention are designed as radar, infrared and/or ultrasonic sensors, usually project beyond the exterior of the vehicle, the appearance of the vehicle is improved since only one set of the means is provided for two functions.
In a development of the invention, when the vehicle is at a speed above a desired value, in particular equal to or slightly greater than zero, the means for sensing objects act as a parking aid, and below this desired value the means for sensing objects act as an opening brake for the opening operation of the tailgate. Consequently, when the vehicle is stationary, the opening brake can be activated when the tailgate is opened and an obstacle is established, whereas, when the vehicle is parking, the warning signal is transmitted to the driver. This avoids the situation where the opening brake is activated, for example, when the vehicle is parking and an approaching obstacle is established.
In a development of the invention, when an object is sensed during the opening operation, the opening operation is braked or stopped. Provided for this purpose are means which, in dependence on an output signal of the means for sensing objects, brake the continuing opening movement of the tailgate or even stop it briefly. These means for braking or for stopping the opening operation may be integrated, for example, in the gas-pressure shock absorbers, but may also be configured as a separate component and, if appropriate, as a counter-drive. It is also conceivable for these means to be provided in the articulation of the tailgate on the vehicle bodywork (for example in the form of a block brake).
In a development of the invention, a sensor is provided for sensing the opening position of the tailgate, with the result that, when the means function as an opening brake, the sensing of objects is only permitted from a predeterminable opening position of the tailgate. It is assumed here that, once the tailgate has been unlocked, the latter either can travel a certain opening distance automatically or is made to travel this opening distance manually by an individual before the means for sensing objects are activated. This is intended to achieve the situation where the tailgate can be opened to a sufficient extent without braking or stopping, a sufficient opening being one where the tailgate does not yet go beyond the outer contours of the vehicle. It is only when a position which exceeds or is equal to a position corresponding to a position in which the tailgate lies beyond the outer contours of the vehicle has been established that the means for sensing objects are activated or the output signal thereof is released for further processing. If a predeterminable opening position has thus been reached or exceeded, it is possible, when obstacles have been sensed, for braking to be initiated or for the continuing movement of the tailgate to be stopped. It is thus the vehicle user""s responsibility to move the tailgate automatically to the predeterminable opening position without the braking operation or stopping being initiated. It is only when the opening operation causes the tailgate to pass into a region which lies beyond the vehicle contours that the automatic mechanism for braking or stopping is activated.
In a development of the invention, in dependence on their respective functions (parking aid/opening brake), the means have different sensing characteristics. It may be provided instead, while maintaining the same sensing characteristics, for the output signal of the means to be evaluated differently. Whereas, for the parking aid, there is a distance of a number of meters before an obstacle appears, and the parking operation takes place relatively slowly, it may be necessary, during the opening operation of the tailgate, for the advancement of the tailgate up to the obstacle to be sensed, and for the continuing movement to be braked or stopped, relatively quickly during this opening operation since, in this case, the distances from obstacles are smaller than when the vehicle is parking. This renders necessary the use of different sensing characteristics or a different evaluation of the output signal of the means for sensing objects.
In a development of the invention, the means are arranged on the bottom border of the tailgate in the closed state of the latter. Consequently, these means are arranged, in the closed state, at a location from which, when the vehicle is parking, other vehicles can be sensed very well. Moreover, during the opening operation, the bottom border of the tailgate covers the greatest possible distance, with the result that very precise sensing of obstacles during the opening operation is possible. The bottom border of the tailgate is usually also that part of the tailgate which, were an obstacle to appear, would be the first region to strike against this obstacle. If, on account of the geometrical configuration of the tailgate, this is not the case, then it should be taken into account correspondingly in the sensing characteristics of the means for sensing objects.